JPH08222194A - Button type alkaline battery - Google Patents

Abstract

PURPOSE: To provide a battery suppressing the generation of hydrogen gas in a battery and reducing the capacity deterioration by forming the face of a negative electrode terminal board to be kept in contact with a negative electrode material with a copper alloy having the zinc content of a specific wt.% and having the lead content and tin content of specific range wt.% respectively. CONSTITUTION: This button type alkaline battery uses zinc of silver anhydride as a negative electrode active material. The face of a negative electrode terminal board 5 to be kept in contact with a negative electrode material 3 is formed with a copper alloy 9 having the zinc content of 30-40 wt.%, the lead content of 0.1-4wt.%, and the tin content of 0.2-0.7wt.%. A button type alkaline battery effectively suppressing the generation of hydrogen gas from the negative electrode terminal board 5 kept in contact with the negative electrode material 3 containing zinc of silver anhydride and reducing the capacity deterioration during storage is obtained. When the zinc content is smaller than 30wt.%, hydrogen gas is easily generated from the negative electrode terminal board 5. When the zinc content is larger than 40wt.%, the machining property is deteriorated when the negative electrode terminal board 5 is manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a button type alkaline battery using anhydrous silver as a negative electrode active material, and more particularly to a button which suppresses generation of hydrogen gas in the battery and has little capacity deterioration during storage. Type alkaline battery.

[0002]

2. Description of the Related Art Generally, in a button type alkaline battery, when zinc is used as a negative electrode active material as it is, zinc dissolves in an alkaline electrolyte while generating hydrogen gas, which causes so-called self-corrosion. The self-corrosion of zinc was suppressed by using zinc amalgamated as a negative electrode active material.

However, recently, from the viewpoint of preventing environmental pollution, there has been a strong demand for the use of anhydrous silver, and zinc has been produced with less self-corrosion with anhydrous silver. (JP-A-62-40163), and also in alkaline batteries, silver-free conversion is being studied. However, in button-type alkaline batteries, the use of anhydrous silver zinc solves the problem of zinc generating hydrogen gas in the alkaline electrolyte during storage and causing self-corrosion, causing swelling and capacity deterioration of the battery. I couldn't.

Therefore, hydrogen is generated by using copper for the surface of the negative electrode terminal plate that contacts the negative electrode agent or by alloying zinc with a metal having a high hydrogen overvoltage, such as lead, indium, bismuth, or tin (tin). It has been attempted to suppress battery swelling and prevent battery swelling and capacity deterioration (for example, JP-A-6-13071).

[0005]

However, in the button-type alkaline battery using anhydrous zinc as a negative electrode active material, copper is used on the surface of the negative electrode terminal plate in contact with the negative electrode agent as described above, and zinc is used as the negative electrode active material. Using only an alloy powder of a metal having a high hydrogen overvoltage, the capacity deterioration during storage was large, and a button-type alkaline battery with a small capacity deterioration could not be obtained.

The inventors of the present invention have investigated the cause of this problem. As a result, in a button-type alkaline battery using anhydrous zinc as a negative electrode active material, hydrogen gas is generated from the copper surface of the negative electrode terminal plate during storage, which causes It was found that the capacity of the battery was significantly deteriorated. It is considered that such generation of hydrogen gas from the copper surface of the negative electrode terminal plate is caused by the copper of the negative electrode terminal plate and zinc of the negative electrode active material forming a local battery. As a result, a button-type alkaline battery using silver anhydrous zinc as a negative electrode active material has a problem that it cannot obtain a long life as required when used in a wristwatch, an electronic exposure meter, or the like.

Therefore, the present invention provides a button-type alkaline battery using anhydrous zinc as a negative electrode active material.
It is an object of the present invention to provide a button-type alkaline battery that suppresses generation of hydrogen gas in the battery and has less capacity deterioration during storage.

[0008]

According to the present invention, in a button type alkaline battery using anhydrous zinc as a negative electrode active material, the surface of the negative electrode terminal plate in contact with the negative electrode has a zinc content of 3%.
Contains 0-4% by weight, a lead content of 0.1-4% by weight, and a tin (tin) content of 0.2-0.7% by weight, thereby containing anhydrous silver zinc. Effectively suppress the generation of hydrogen gas from the negative electrode terminal plate in contact with the negative electrode agent,
A button type alkaline battery with less capacity deterioration during storage is obtained.

In the present invention, the copper alloy constituting the surface of the negative electrode terminal plate which is in contact with the negative electrode agent needs to contain 30 to 40% by weight of zinc, which has a zinc content of less than 30% by weight. In this case, hydrogen gas is likely to be generated from the negative electrode terminal plate, and if the zinc content is more than 40% by weight, workability in manufacturing the negative electrode terminal plate is deteriorated.

The above copper alloy has a lead content of 0.1 to 4
It is necessary that the weight% and the tin content are 0.2 to 0.7% by weight for the following reason. That is, when the lead content is less than 0.1% by weight, hydrogen gas is easily generated from the negative electrode terminal plate due to hydrogen overvoltage, and when the lead content is more than 4% by weight, the negative electrode terminal plate is manufactured. The workability at the time becomes worse. When the tin content is less than 0.2% by weight, hydrogen gas is likely to be generated from the negative electrode terminal plate, and when the tin content is more than 0.7% by weight, workability in manufacturing the negative electrode terminal plate is improved. Deteriorate.

The copper alloy contains 30 to 40% by weight of zinc, 0.1 to 4% by weight of lead, and 0.2 to 0.7% by weight of tin as described above. Has a copper content of 55.3% by weight and a copper content of 69.7% by weight.

As described above, the negative electrode terminal plate has a zinc content of 30 to 40% by weight and a lead content of 0.
It is composed of a copper alloy having 1 to 4% by weight and a tin content of 0.2 to 0.7% by weight, but its main body portion is usually made of stainless steel and has an outer surface side, that is, a surface in contact with the negative electrode agent. The opposite surface is composed of nickel. However, these are not necessarily limited.

Next, an example of the button type alkaline battery of the present invention will be described with reference to the drawings. However, the present invention is not limited to this example.

FIG. 1 is a partial cross-sectional view schematically showing an example of the button type alkaline battery of the present invention, and FIG. 2 is A in FIG.
FIG.

In the figure, 1 is silver oxide, manganese dioxide,
It is prepared by press-molding a mixed powder of a positive electrode active material such as silver (II) oxide, nickel hydroxide, etc. and a conductive auxiliary agent such as carbon black, graphite, graphite on a disk, and then adding it to an alkaline electrolyte. 2 is a separator interposed between the positive electrode mixture 1 and the negative electrode agent 3, and the separator 2 is, for example, a hydrophilic microporous polypropylene. It is a stack of a film, a cellophane film and a liquid absorbing layer such as a vinylon-rayon mixed paper. Reference numeral 3 is a negative electrode agent containing a negative electrode active material composed of anhydrous zinc and a gelling agent such as sodium polyacrylate and carboxymethyl cellulose, which is optionally added, into which most of the alkaline electrolyte is injected. .

Reference numeral 4 denotes a positive electrode can made of iron having the positive electrode mixture 1 and the separator 2 filled therein, and the surface of which is nickel-plated.
The negative electrode terminal plate 5 having the negative electrode agent 3 filled in the opening is fitted with an annular gasket 6 having an L-shaped cross section made of various resins such as polyethylene and polypropylene or rubber, and fitted. The end portion is tightened inward and the annular gasket 6 is brought into contact with the negative electrode terminal plate 5 to seal the end, thereby forming a sealed structure inside the battery.

As shown in FIG. 2, the negative electrode terminal plate 5 is provided with a nickel layer 8 satisfying aesthetics and corrosion resistance on the outer surface of a stainless steel plate 7, and a copper alloy on the inner surface, that is, the surface in contact with the negative electrode agent 3. The copper alloy layer 9 has a zinc content of 30 to 40% by weight and a lead content of 0.
It is composed of a copper alloy having 1 to 4% by weight and a tin content of 0.2 to 0.7% by weight. The negative electrode terminal plate 5 is usually produced by drawing a clad plate made of the stainless steel plate 7, the nickel layer 8 and the specific copper alloy layer 9 into a shape having the peripheral folded portion 10. . Although not shown, a rust-preventive coating containing a triazole-based compound as a main component is provided on the surface of the peripheral folded-back portion 10 of the negative electrode terminal plate 5 and the copper alloy layer 9 in the vicinity thereof to improve liquid leakage resistance. There is.

[0018]

EXAMPLES Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples illustrated in the embodiments.

Examples 1 to 4 and Comparative Examples 1 to 4 A clad plate composed of a nickel layer / stainless steel (SUS-304) plate / copper alloy layer is punched by a press machine and has a peripheral folded portion as shown in FIG. It processed into the shape and produced the negative electrode terminal plate. The composition of the copper alloy of the negative electrode terminal plate is as shown in Tables 1 and 2.

The positive electrode active material is silver oxide, the negative electrode active material is anhydrous zinc, and the electrolytic solution is a 35 wt% potassium hydroxide aqueous solution containing 5 wt% of zinc oxide. A button type alkaline battery having an outer diameter of 6 mm and a thickness of 2.6 mm was manufactured by using the negative electrode terminal plate of No. 1 having the structure shown in FIG.

With respect to the obtained batteries, the gas generation amount and the capacity retention rate were examined, and the results are shown in Table 1 according to each battery.
~ 2.

The gas generation amount is measured by storing each battery at 60 ° C. for 40 days, decomposing the stored battery in a graduated cylinder filled with liquid paraffin, and collecting the generated gas. The capacity retention was measured by discharging 100 batteries before storage at 20 ° C. and 15 kΩ to measure discharge capacity, and storing 100 batteries different from the above at 60 ° C. for 40 days and then at 20 ° C., The discharge capacity was measured by discharging at 15 kΩ, and the ratio of the discharge capacity after storage to the discharge capacity before storage was determined by the following formula.

[0023]

[0024]

[Table 1]

[0025]

[Table 2]

As can be seen from the comparison between the characteristics of the batteries of Examples 1 to 4 shown in Table 1 and the characteristics of the batteries of Comparative Examples 1 to 4 shown in Table 2, the batteries of Examples 1 to 4 exhibited gas generation. The quantity was small, the capacity retention rate was high, and the capacity deterioration due to storage was small.

[0027]

As described above, according to the present invention, in a button-type alkaline battery using anhydrous zinc as a negative electrode active material, the surface of the negative electrode terminal plate in contact with the negative electrode has a zinc content of 30 to 40% by weight. By using a copper alloy having a lead content of 0.1 to 4% by weight and a tin content of 0.2 to 0.7% by weight, generation of hydrogen gas in the battery is suppressed, and It was possible to provide a button-type alkaline battery with little capacity deterioration.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view schematically showing an example of a button type alkaline battery of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

[Explanation of symbols]

 1 Positive Electrode Mixture 2 Separator 3 Negative Electrode 4 Positive Electrode Can 5 Negative Terminal Plate 6 Annular Gasket 7 Stainless Steel Sheet 8 Nickel Layer 9 Copper Alloy Layer

Claims (1)

[Claims] 1. In a button type alkaline battery using anhydrous zinc as a negative electrode active material, the surface of the negative electrode terminal plate in contact with the negative electrode agent has a zinc content of 30 to 40% by weight and a lead content of 0.1. A button-type alkaline battery comprising a copper alloy having a content of 4 wt% to a tin content of 0.2 to 0.7 wt%.